Perfume fixatives comprising polyvinylpyrrolidone and hydroxypropyl cellulose

ABSTRACT

A perfume fixative consisting essentially of polyvinylpyrrolidone, hydroxy propyl cellulose and hydrophobic oil. The perfume fixative is being incorporated in a perfume-containing formulation or product. The fixative is found to be effective in enhancing perfume life, even when utilized at low levels.

This application is the national phase of international applicationPCT/GB98/01381 filed May 14, 1998 which designated the U.S.

FIELD OF THE INVENTION

This invention concerns perfume fixatives, that is, compositionsintended for use in perfume-containing formulations to enhance fragrancelife. The words “perfume” and “fragrance” are used synonymously in thisspecification and no significance should be attached to the choice ofword used in any particular context. The invention includes within itsscope perfume fixatives, mixtures of perfume and fixative, mixtures ofproduct base and fixative, and perfumed products including perfume andfixative.

BACKGROUND OF THE INVENTION

Fragrances in some products such as perfumed leave-on skin products,particularly (but not exclusively) ethanol-based ones eg (deo)colognes,personal perfumes, anti-perspirant deodorants, hair colognes etc, tendto lose their character rapidly ie the top/middle notes evaporate. Thereis a desire to extend the life of such perfumes, particularly inretaining the initial character and intensity of the fragrance, andvarious perfume fixatives have been proposed. It is an importantpractical consideration that the fixative should not adversely affectthe aesthetic character of the product, ie the fixative should not bediscernible by the user.

PRIOR ART

Various fixative systems have been proposed including fixative oils (egGLUCAM P20 (GLUCAM is a Trade Mark)) or film-forming polymers. Theformer require the use of relatively high levels of oil to producenoticeable effects, whilst when the latter are effective they producevery noticeable films (both visual and tactile). Various perfumecarriers/encapsulates have also been proposed but suffer from problemswith cost and visibility in the product and/or on the skin/hair. JP62114909 discloses use of 1 to 60 wt % of polyvinylpyrrolidone (PVP) and1 to 30 wt % of hydroxypropyl cellulose (HPC) with a fragrance materialto produce a long lasting fragrance. Such levels of PVP and HPC would bevery readily noticeable to the consumer.

SUMMARY OF THE INVENTION

In one aspect the present invention provides a perfume fixativecomprising:

(a) polyvinylpyrrolidone;

(b) hydroxypropyl cellulose; and

(c) hydrophobic oil.

Polyvinylpyrrolidone (PVP) is readily commercially available in a rangeof molecular weights. The molecular weight of the PVP is not critical,but in general it is thought that PVP of higher molecular weights givesbetter performance. Good results have been obtained with the highmolecular weight PVP LUVISKOL K90 (LUVISKOL is a Trade Mark) from BASF.A mixture of different PVPs may be used.

Hydroxypropyl cellulose (HPC) is similarly readily commerciallyavailable in a range of molecular weights. Higher molecular weight HPCgives better performance but also has a thickening effect, so it ispreferred to use medium molecular weight HPCs as a compromise betweenperformance and product compatibility. Good results have been obtainedwith KLUCEL G (KLUCEL is a Trade Mark) from Aqualon. A mixture ofdifferent HPCs may be used.

The hydrophobic oil should be non-ionic oil which is liquid at skintemperature (typically about 35° C. under normal conditions).

The hydrophobic oil suitably has an octanol/water partition co-efficient(log P) greater than 3,preferably greater than 5.

The hydrophobic oil suitably has a Hildebrand's solubility parameter(δ_(HILD)) (Hildebrand, J. H. & Scott, R. L. The Solubility ofNonelectrolytes, 3rd edition, Reinhold, New York, 1950) of less than 20MPa^(½), and preferably greater than 14 MPa^(½).

For obvious reasons, the hydrophobic oil should be odourless, of lowodour, or of neutral or inoffensive odour.

The hydrophobic oil should also be non-volatile, preferably having avapour pressure of less than about 0.01 mm Hg.

The hydrophobic oil is preferably an ester and/or (poly)ether. Estersare currently the most preferred materials.

Suitable hydrophobic oils include:

Propylene glycol dicaprate/dicaprylate, ie C8, C10 diester withpropylene glycol, eg as MIGLYOL 840 (MIGLYOL is a Trade Mark) from Huls.

Dioctyl adipate

Isopropyl myristate

Glycerol monooleate

POE(10) cetyl ether

POE(20) sorbitan monolaurate

Dibutyl phthalate

Acetyl tributyl citrate

POE is an abbreviation for poly(oxyethylene) ether.

The currently preferred material is MIGLYOL 840.

A mixture of hydrophobic oils may be used.

The proportions of the 3 ingredients in the fixative are not critical.

Preferably the PVP and HPC together constitute at least 30%, morepreferably at least 40%, by weight of the total weight of the fixative.

The oil preferably constitutes at least 10% by weight of the totalweight of the fixative.

The composition typically comprises equal amounts by weight of PVP andHPC but this is not essential, and there may be cases where it isadvantageous for the amount by weight of the HPC to exceed that of PVP.

Good results have been obtained with fixatives comprising, by weight,25% PVP, 25% HPC and 50% hydrophobic oil.

A typical fixative formulation consists of:

MIGLYOL 840 50.0 wt % non-volatile oil

LUVISKOL K90 25.0 wt % PVP, high molecular weight

KLUCEL G 25.0 wt % HPC, medium molecular weight

The perfume fixative is used by being incorporated in aperfume-containing formulation or product. The fixative is found to beeffective in enhancing perfume life, even when the fixative is used atlow levels. The efficacy even at low levels is surprising andunexpected, and the reason for this efficacy is not yet known.

For practical reasons, the PVP and HPC together should not constitutemore than about 0.5%, preferably not more than about 0.25%, by weight ofthe perfume-containing product. If these materials are present at higherlevels they are discernible by the user, either by sight or feel, whichis undesirable. However, the fixative is found to be effective in anamount corresponding to this constraint and also at lower levels.

For example, for a perfumed product containing 1% by weight perfume(which is typical of the perfume levels in a deodorant), aperfume:fixative weight ratio of at most 2:1 satisfies the abovepreferred constraint (for a fixative comprising 50% by weight PVP andHPC), and this is found to be more than adequate to obtain good results.Indeed, useful effects are obtained with considerably smaller amounts offixative, eg with perfume:fixative weight ratios of 9:1 or even 19:1which correspond to combined PVP and HPC weights of 0.055% and 0.026%,respectively (for a fixative comprising 50% by weight PVP and HPC).

For perfumed products with higher perfume levels, such as personalperfumes and fine fragrances which typically contain perfume in anamount in the range 2 to 25 % by weight, even higher perfume:fixativeweight ratios can be effective.

The most effective level of the fixative depends upon the nature of theperfume and the amount in which it is used, and this can be determinedby experiment.

The fixative may be used with a wide range of perfumes, although bestresults are obtained with perfumes that are not very substantive, iethose perfumes that are most in need of improvement.

For incorporation in a perfume or perfumed product, the fixative may bepre-mixed with perfume and then added to product base (which is allproduct ingredients except perfume). Alternatively the fixative may beadded to the perfumed product (ie product base and perfume). As afurther possibility, the fixative may be added to the product base, andperfume then added.

In a further aspect, the invention thus provides perfume mixed withperfume fixative in accordance with the invention.

The invention also covers a product base mixed with perfume fixative inaccordance with the invention.

Another aspect of the invention covers a perfumed product comprisingperfume fixative in accordance with the invention.

The invention is applicable to a wide range of perfumed products wherefragrance life is a consideration, including perfumed leave-on skinproducts, including ethanol-, water- and silicone-based products, suchas colognes, deo-colognes, personal perftnes, deodorant, antiperspirantdeodorants, hair colognes etc.

A typical deodorant has the following composition:

Ethanol 80.0 wt % Water to 100.0 wt % Fragrance 1.00 wt % Fixative Blend0.50 wt % Trielosan 9.25 wt %

The fixative conveniently comprises, by weight, 50% MIGLYOL 840, 25%LUVISKOL K90 and 25 % KLUCEL G, as discussed above.

The invention will be further described, by way of illustration, in thefollowing Examples.

EXAMPLE 1

(Cologne)

The following example illustrates the improvement in performance thatcan be produced using a classic citrus cologne perfume. The perfumetested comprised the following ingredients:

Citrus Cologne Perfume A wt % Nonanal 0.2 Decanal 0.4 Benzyl Acetate 5.0Camphor 0.4 Cineole 0.4 Citral Lemarome 0.7 Geraniol 5.0Hydroxycitronellal 2.0 Limonene Dextro 40.0 Linalol 10.0 Linalyl Acetate16.0 Lyral (IFF) 2.0 Methyl Dihydro Jasmonate Super (Q) 2.0 MyrcenylAcetate 3.0 Terpinyl Acetate 12.9 (G) - Givaudan-Roure SA (Q) - Quest

Three colognes were prepared by simple mixing as follows:

wt % Reference Test 1 Test 2 Test 3 Citrus Cologne Perfume 2.0 2.0 2.02.0 Ethyl alcohol 79.6 78.8 78.8 78.8 Distilled water 18.4 18.2 18.218.2 LUVISKOL K90 — 0.25 0.25 0.5 KLUCEL G — 0.25 0.25 0.5 MIGLYOL 840 —0.50 — — MYVEROL 18-99 — — 0.50 —

MYVEROL 18-99 (MYVEROL is a Trade Mark) is mainly glycerol mono-oleateand is available from Quest International.

The colognes were tested by a paired comparison test where 50 μl of eachsample was placed using a calibrated pipette onto marked areas of asubject's forearms (one sample per arm!), all of whom were expertperfume evaluators. The test colognes were self-assessed by each subjectafter one and four hours relative to their reference colognes and thefollowing average scores were obtained (0-5 scale):

Average of 5 Subjects Reference* Test 1 Comments One Hour 3.0 4.1Noticeably stronger and fresher Four Hours 2.0 2.7 Stronger, more citrusodour Average of 5 Subjects Reference* Test 2 Comments One Hour 3.0 3.5Stronger and fresher top-note Four Hours 2.0 2.8 Much stronger Averageof 5 Subjects Reference* Test 3 One hour 3.0 3.5 Four hours 2.0 2.5*Scores fixed for reference

EXAMPLE 2

(Aerosol)

Test 3 illustrates a fixative:perfume level of 1:2

Test 4 illustrates the same fixative but at 1:9 fixative:perfume

Test 5 illustrates a slightly changed fixative at ˜1:19 fixative:perfume

The following solutions were prepared:

wt % Reference Test 3 Test 4 Test 5 Perfume AP209*  1.0 1.0 1.0 1.0Ethyl alcohol 99.0 98.5 98.89 98.95 LUVISKOL K90 — 0.125 0.028 0.016KLUCEL G — 0.125 0.028 — MIGLYOL 840 — 0.25 0.056 0.032 KLUCEL E (Low —— — 0.006 Molecular weight HPC) *available from Quest

These solutions were then made up into standard aerosols using apropellant:solution ratio of 65:35,where the propellant was a standardpropane/butane mix. The aerosols were then tested in an analogous mannerto the colognes, but using a fixed spray time 3 seconds at a fixeddistance of 15 cm from the arm.

Average of 5 Subjects Reference Test 3 Comments Initial 4.8 4.9 One Hour3.6 3.8 Four Hours 2.3 2.9 Reference flat in comparison Eight Hours 0.61.5 Almost nothing left of the reference Average of 5 Subjects ReferenceTest 4 Comments Initial 4.5 4.9 One Hour 3.8 4.3 Four Hours 2.5 3.3Clear difference in strength/ freshness Eight Hours 1.5 2.2 Still animpressive difference Average of 5 Subjects Reference Test 5 CommentsInitial 5.0 4.9 One Hour 3.8 3.8 Four Hours 1.2 2.0 Test 5 much fresherEight Hours 0.5 1.0 Clear difference

What is claimed is:
 1. A perfume fixative consisting essentially of: (a)polyvinylpyrrolidone; (b) hydroxypropyl cellulose; and (c) anon-volatile hydrophobic oil having a vapour pressure of less than about0.01 mm Hg.
 2. A perfume fixative according to claim 1, wherein thehydrophobic oil is selected from the group consisting of an ester and(poly)ether.
 3. A perfume fixative according to claim 2, wherein thehydrophobic oil comprises one or more selected from the following:Propylene glycol dicaprate/dicaprylate Dioctyl adipate Isopropylmyristate Glycerol monooleate POE(10) cetyl ether POE(20) sorbitanmonolaurate Dibutyl phthalate Acetyl tributyl citrate.
 4. A perfumefixative according to any one of the preceding claims, wherein thepolyvinylpyrrolidone and hydroxypropyl cellulose together constitute atleast 30%, preferably at least 40%, by weight of the total weight of thefixative.
 5. A perfume mixed with an effective amount of perfumefixative in accordance with claim
 1. 6. A perfumed product comprising aneffective amount of perfume fixative in accordance with claim
 1. 7. Aperfumed product according to claim 6, wherein the polyvinylpyrrolidoneand hydroxypropyl cellulose in the fixative together constitute no morethan about 0.5%, preferably no more than about 0.25%, by weight of thetotal weight of the perfumed product.
 8. The method which comprisesproviding a perfumed leave-on skin product containing the perfumefixative of claim 1 and applying said perfumed leave-on skin product tohuman skin.
 9. A method of preparing a perfume or a perfumed productcomprising providing a perfume fixative according to claim 1 and mixingan effective amount of said perfume fixative with a perfume.
 10. Amethod according to claim 9 wherein the perfume or perfumed product is aleave-on skin product.
 11. A perfume fixative according to claim 4wherein the polyvinylpyrrolidone and hydroxypropyl cellulose togetherconstitute at least 40% by weight of the total weight of the fixativeand the balance is a hydrophobic oil selected from the group consistingof Propylene glycol dicaprate/dicaprylate Dioctyl adipate Isopropylmyristate Glycerol monooleate POE(10) cetyl ether POE(20) sorbitanmonolaurate Dibutyl phthalate Acetyl tributyl citrate.
 12. A perfumedproduct according to claim 6 wherein the polyvinylpyrrolidone andhydroxypropyl cellulose together constitute no more than about 0.25% byweight of the total weight of the perfumed product.
 13. A perfumefixative according to claim 1 containing 25% polyvinylpyrrolidone, 25%hydroxypropyl cellulose and 50% hydrophobic oil.